Zeolites contain micropores having a uniform pore size distribution with a margin of error of 0.1 Å or less. Hence, these substances display their unique shape selectivity that does not appear in the amorphous oxides. Due to such a characteristic, zeolites are widely used as an ion-exchanger, a catalyst, or a catalyst support in various fields of fine chemistry, petroleum chemistry, etc. Particularly, zeolites are superior to other inorganic materials in regards to gas permeability and selectivity due to their molecular sieve effect that the substances being adsorbed into the micropores are determined by the size of the micropores and the molecules to be adsorbed. Besides, zeolites are excellent in thermal/mechanical stability and highly available as an adsorption-based eliminator or separator because of its ability to control the polarity through adjusting the Si/Al molar ratio or performing the cation exchange.
The organic structure directing agents (OSDAs) such as amine and alkyl ammonium ions have been used for several decades since the first introduction of the hydrothermal synthesis methods by Barrer and Milton in the 1940s, and 218 zeolites have been reported until 2014. The structures of the zeolites are disclosed in Atlas of Zeolite Structure Types, Butterworth 2007, http//www.iza-structure.org/.
The zeolites for commercial use need to meet some requirements such as micropore size, structure, acidity, hydrothermal stability, etc., as suitable to the applied fields, so only about eighteen types of zeolites, including LTA, FAU, MFI, MOR, BEA, FER, LTL, etc. are now commercially available.
The zeolite with novel skeletal structure and composition is very critical because it enables the innovative improvement of the existing chemical processes and the development of numerous processes of great importance from a commercial point of view. Accordingly, there is a continuous demand for a novel zeolite having a new structure.